Secondary or storage battery



Apr. 3, 1923. 1,450,565

g E. W. SMITH SEONDARY OR STORAGE BATTERY Fi led Jan. 30 1922 PatentedApr, 3i, i923.

entre srArEs "PATENT OFFICE.

EDWARD W. SMITH, 0F PHILADELPHIA, PENNSYLVANIA.

SECONDARY OR- STORAGE BATTERY.

Application led January 30, 1922.

taining the active material and metallic cores which act as conductors,and of a frame to unite the various tubes into a single unit.' Howeverthe invention is confined to such plates in which the tubes consist ofhard rubber, and in which the necessaryV porosity is secured by a largenumber of saw slots placed very close together.

It is found in practice that, though far c moredurablethan. othertypessuchy a slotted rubber plate is subject to wear chiefly in the slowoxidation of the rubber tube from within, so that in time it becomesthinner and thinner, and eventually fails entirely.

The present invention has for its object the virtual elimination of thatsource ot failure, and this is accomplished by means cfa lining ofasbestos in the forni .of paper within the slotted rubber tube. rlhethin asbestos in the form of paper, may con-l veniently be formed into'a tube and slipped into the slotted rubber tube, or may be deposited4from a water emulsion `in a thin layendirectly upon the inner surface ofthe slot-ted tube.

The invention may be more readily understood by reference to theaccompanying drawings in which Figures l, Q and 3 represent respectivelyside views and an end view of a tube torming one unit of a batteryplate, and

Figs.: 4 and 5 represent respectively side and end views of `a modiiedtube unit.

Referring more especially to Figs. l to 3, 6 is a central metallicconducting and supporting core, by means of which the whole lunit isunited to the rest 'of the plate, in a manner well known to those versedin vthe `art, 5 is the active material, consisting 'of Serial No.532,727.

lead peroxide in the usual type of lead battery, while. 2 is theencircling slotted rubber tube, which acts as a retainer for the activematerial which in it'seltl is possessed of but little cohesion. Thetube, as illustrated, consists of solid, uncut,longitudinal strips orribs 3 and semi-circular rings 2 formed by making a number of saw cutsthrough the wall ofthe original solid walled tube. Between the activematerial 5 and the rings of the tube 2. is the thin layer or tube ofasbestos in the form of paper 1 finely porous throughout. but withoutthe saw cuts,

and therefore constituting a continuous tube the whole length of theunit.

In FigsA land 2 the asbestos protecting layer in the form of paper isshown turned back slightl)v over the end of the tube at 7 for thepurpose of insuring that none of the rubber t-ubc at its end shall beleft unprotected.

In Figs. 4 and 5 the unit differs in that the longitudinal strips areentirely lacking, and the retaining tube consists merely of a number ofthin rings 2?, placed close toget her, and surrounding the protectinglayer l of asbestos in the form of paper and the active material 5. a

It will be remarked that the selection of asbestos in the form of paperand rubber in the forni of slotted tubes prevents contact between theactive material and the small retaining portions of Vthe tube betweenthe slots, and thus protects those small portions 'of the tube from thechemical action of the active material'. which tends to disinte ate themfrom the interior of the tube whi e at the same time the asbestos inpaper form bridges across the minute openings of the ysaw slots thusvery perfectly retaining the active material in place.

It will be readily understood that the invention involves inthecombination not only the selection of particular materials, asbestosand rubber, from amongv other materials heretofore used or suggested butalso the selection or the form 'of aper and the form of a slotted tubevin which to embody those materials and it will be also understood thatby the described selection of og'm and inaterial a long existing defectarising from the chemical action of the active material on tbe barsbetween the slots is corrected.

I claim:

ln a storage. battery plate of tubular type the Combination of rubber inthe form of a slotted tube and of asbestos in tbe form of paper arrangedinside of and lining said tube with artive material and a metalliccentral supporting core also arranged in tlio tube, wbereb) rubber inthe Jform stated is protected b v tbe asbestos in tbe form Set fortbfrom tbe rbemieal action of tbe artire material.

luDlVARD W. SMITH.

